Piano action



Nov. 9 1926. 1,606,671

G. SMULDERS PIANO ACTION Filed Jan. 19 1925 Patented Nov. 9, 1926.

1 UNITED STATES cannsiuurinnns, or LIEGE, BELGIUM.

ACTION.

.Applicationnled Janua y 9 49 fi i 25, and in Belgium February 13, 1924.

The present invention has for. its object a piano action, in, which. improved means. are provided for projecting 'andreleasing the hammer in suc-hamanner, asto; permit the latter to efiiciently and rapidly repeat. its stroke or strokes against the string.

The, object of the present invention may beapplied as well. to. grandpianos andito upright pianos as to .player'pia'nos.

The annexed drawing representsby wayv of example:

Figure 1 the essential parts. of a pianoaction-unit as used in connection with grand pianos, constructed according to the present invention.

Figure 2 theessential parts of a piano.- action-unit, as used in, connection with upright pianos, constructed in accordance with the present'invention. 7

According to Figure 1, the action unit comprises the following usual parts: a ham mer 1, pivoted at 1 to-thehammer support 1; a key 2, having its fulcrum at 3; an adjusting screw called the pilot t'fixed upon the inner end ofth'e' key 2;. a. guiding link 5, pivoted at 5 tothecorresponding support 5"; an adjustable releasing screw-6 within the, hammer support 1"; a jack -7 pivoted at 8 to the guiding link 5.; said jack being formed with a projecting part or finger 7 acted upon. by the compressible spring 11, whichlat-ter provokes the, jack to bear against thejack-rest 9.'

A usual pushing'rod. 12 may beprovided upon the hammer rodl, to cooperate with the spring 11. However, according, to the object of the present invention this pushing rod may be readily dispensedv with.

in the usual piano actions, the jack is provided with a pin or spur which enters into contact with the releasing screw, as soon as the hammer head; arises at a distance of about 2 or 3 millimeters from the string. N ow, the inner or rear end ofthe key must continue its upward movement, as the releasing movement of. the jack. depends from this upward movement of the rear end or" the key. However, in the. piano actions known up to this time,.the guiding link, as .well as. the. jack participate in this last mentioned ascending vmovement of the rear end of the key. Moreover in the usual piano=actions, this common ascending movement ofthe mentioned parts must eX- ceed the ratio which would be suiiicient to provoke the releasing movement of the jack,in orderto approach the hammer rest to the hammer head, which hammer restis secured to said inner end. of the. key. Thus when the inner endofthejkey terminates its ascending movement, the summit of, the 'jack is disposed at a considerably higher level than at the movementin which the spur or. the jack enteredinto contact with the releasing screw. This, is the ground of the difiiculty to construct-a perfectly well operating piano action, because the exceedingly raised position ofthe jack hinders the hammer to efficiently fall. back after the stroke, the necessity of obviating these inconveniences being the reason why the usual piano actions are so complicated in construction. I

Apording to the present invention all these difficulties are obviated in anovelsimple and very eflicient manner. According to the object of the present invention ,it is not the mentioned spur of the jack which is arrested or stopped,.but. the guiding link itselil. Thus, as soon as the guiding link is arrested, only the inner end of the key continues to move upwards, whereas ,the guiding link remains in its stopped position, that. is to say, at the same level, the summit-of the jackexecuting at the same time a descending movement, by virtue of a rocking movement of the jack upon the arrested guiding link. It is evident, from thepreceding explanation tliatthe arresting of thecomhined guiding link and jack in their upward. movement, is of prime importance because it assures an easy releasing of the hammer and the possibility of a rapid stroke repetition.

Moreover, according to the'object of the present-invention the jack always r'emains with, the hammer in a contact; which per.-

mits the hammer to be easily andefficiejntly projected from all successive positions of the jack.

"Referring principally to Figure '1 of the annexed drawing, the upper extremity of the jack '2' forms an enlargedand preferably curved headrportion 7", which may be and to reiease the hammer, as soon as the guiding link is arrested in its upward movement. The pivot 5 of the guiding link 5 is disposed at a higher level than the pointof contact between the heel-portion 7 of the jack and the pilot screw 1 oi the key, in order to reduce friction.

The operation of the action unit according to Figure 1 is as follows: so long as the difierent parts remain in their normal position, the head portion 7 of the jack bears against the hammer rod 1 at a point A which is situated at any convenient distance from the hammer pivot 1, whereby the initial displacement of the hammer, and consequently the playing, may be effected with great facility, or by what is so called, an easy touch. As soon as the hammer 1 actuated by the key through the medium of the jack 7, rises, the point of contact between t the head portion 7 of the jack and the hammer rod 1 approaches the pivot point 1 of this latter. Thus, the hammer 1 is finally acted upon by the jack 7 at a. point B, which will be situated at but a very small distance from the pivot 1 of the hammer,

the violence of the final impelment of this latter being thereby considerably increased.

As soon as the hammer head 1 arrives at a distance of about 2 or 3 millimeters from the'string 10, the right hand extremity of the guiding link 5 will be stopped by the adjustable stop screw 6 which is disposed outside the action-unit proper, and thereby readily accessible. Now, as the left hand portion of the key member 2 is continuing to move upwardly, the adjustable screw 1, pressing against the heel-portion 7" of the jack 7, at a point such as for instance C, will oblige the jack to pivot around its axis 8 in an anti-clockwise sense, and consequently to move with its head portion 7 in the direction of the hammer head 1".

If the key is released, the jack 7 rocks in a clockwise direction, due to the pressure of a the spring 11, until it is stopped by the rest 9. An auxiliary pushing rod 12 may be provided upon the hammer-rod 1. This pushing rod moves away from the jack 7 during the projecting movement of the device, whereas during the return movement it approaches the jack and pushes it finally into contact with the rest 9. However, as mentioned above, the pushing rod 12 may readily be dispensed with.

By virtue of this rocking or releasing point or points, as to provoke the movement of the jack 7, the summit of the latter will belowered, this lowering of the j ack-summit permitting in its turn the hammer, after its stroke, to fall back at a greater distance from the string than the distance 2 or 3 millimeters mentioned above, whereby the hammer is brought into a position, from which it readily and eiiiciently may repeat same manner as that described with refer-.

ence to Figure 1. The'summitof the jack 7 practically remains in continuous contact with the elongated hammer butt 13, thus ensuring an infallible repetition. In this construction it would also be possible to provoke the releasing movement of the jack 7 by stopping the link member 5. 7

According to Figure 2, however, the key screw 4 or equivalent part, acts directly upon the guiding link 5, which has its pivot at 14, whereas the stop-screw 6 acts upon the projecting part 7 of the jack 7, to provoke this latter to execute its releasing movement at the desired moment. The jack is held in its normal position by the spring 11.

What I claim is:

1. In a piano action, a ivotally mounted key, a pivotally mounte hammer, and a pivotally mounted guide-link, in combination with a jack pivotally mounted on said link, bearing against said hammer and engaged by said key, means acting on said link and jack tending to maintain the latter in normal operative position, and a stop limiting the movement of said guide-link, said jack being so mounted on the guide link and so related to said key as to be rocked about its pivot by the latter in its continued stroke after said link has been stopped to depress the upper end of said ac 2. In a piano action, a rockably mounted key, a pivotally mounted hammer, and a guide-link mounted to swing in a vertical plane, in combination with a jack rockably mounted on said link, bearing against said hammer and actuated by said key, means acting on said link and jack tending to maintain the latter in normal operative position, a stop for limiting the upward movement of said guide link, and means for rocking said jack after the movement of said guide-link has been arrested to depress the upperend of said jack.

3. In a piano action, a pivotally mounted hammer having arectilinear plane face adhit) jaoent its pivotal mounting, in combination a predetermined point to depress said opera- With a rockably mounted jack having an optive portion thereof. erative portion engaging said face of said In testimony whereof, I have signed my 1 hammer progressively nearer the pivotal name to this specification at Antwerp, Bel- 5 mounting of the latter as the hammer apgium, this 6th day of January, 1925.

proaohes the end of its stroke, and adjustable means for causing said jack to rock at 7 .CARL SMULDERS. 

